Liner removal apparatus

ABSTRACT

A method and apparatus for removing a metallic liner from the inside wall of production tubing downhole in an oil well which includes a longitudinal spear member eccentrically attached to a mandrel and a housing assembly which is adapted for connection to a wireline or other downhole tool. As the end of the spear member is moved between the liner and the tubing, it deforms the liner to produce a reverse bend therein throughout the length of the liner for reducing the diameter of the liner to thereby release same from the tubing for withdrawal from the tubing.

United States Patent 1 Kinley et al.

[ 1 Apr. 17, 1973 LINER REMOVAL APPARATUS [75] Inventors: Jnlm C. Kinley; Walter C. Jefferson, both of Houston, Tex.

[73] Assignee: said Kinley, by said Jefferson [22] Filed: Dec. 20, 1971 [21] Appl. No.: 210,020

[52] US. Cl. ..166/297, 72/370, 166/55, 166/315 [51] Int. Cl. 1521b 29/00 [58] Field of Search ..72/307, 370; 166/315, 55, 277, 553,178, 211, 98, 99

[56] References Cited UNITED STATES PATENTS 1,550,301 8/1925 Yungling 1 66/55 X 9/1957 Potts ..166/98 3,051,254 8/ 1962 McClint0n.. ..l66/99 X 3,358,769 12/1967 Berry 166/207 Primary Examiner--David H. Brown Attorney-Pravel, Wilson & Matthews 5? Y ABSTRACT 19 Clains, 6 Drawing Figures PATENTED APR 1 7 I975 SHEET 2 OF 2 LINER REMOVAL APPARATUS BACKGROUND OF THE INVENTION 1. Field of the Invention The field of this invention is apparatus for removing a liner from a tubular member such as oil well production tubing or casing.

2. Description of the Prior Art In oil well production it is occasionally necessary to repair weak spots in the production tubing which have occurred as a result of corrosion or erosion caused by fluid flowing through the tubing. Also, holes may have been placed in the production tubing for some specific purpose, such as a gas lift installation, and are no longer needed. In either situation it is extremely desirable that these holes or weak spots be covered without having to actually remove the weak or leading tubing a laborious and costly procedure which requires that the well be shut down and the tubing pulled.

Metal liners have been found quite effective for patching holes or weak spots in downhole production tubing. Typically, such metallic liners are thin-walled steel tubing which are coated on the outside with an oilresistant elastomer to provide a seal between the liner and the production tubing.

Various means have been devised for setting a metallic liner in production tubing; for instance, in the US. Pat. No. 3,489,220, issued to M. M. Kinley, a method and apparatus is described for installing a liner having at least one reverse bend therein.

Although the liners are extremely effective once installed, occasionally a newly installed liner does not effectively seal off the weak spot or hole in the tubing or is damaged during service and should be removed. Insofar as known, no one has devised an effective means for removing such a liner from the production tubing so that another liner can be installed.

SUMMARY OF THE INVENTION Apparatus and method is provided for removing a liner from downhole in production tubing without having to remove the tubing therefrom. The method of removing such a liner basically comprises the steps of lowering a substantially longitudinal member downhole and inserting the substantially longitudinal member between the liner and the production tubing to produce a reverse longitudinal bend therein thereby separating the liner from the tubing.

The apparatus of this invention comprises a substantially longitudinal member which includes means forming a reverse bend longitudinally of said liner as the longitudinal member is inserted between the liner and the tubing to effectively reduce the diameter of the liner thereby separating the liner from the tubing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A of the drawings illustrates the upper section of the apparatus of this invention in oil well production tubing;

FIG. 1B of the drawings illustrates the lower section of the apparatus with the spear member of the apparatus positioned above the upper end of the liner to be removed;

FIG. 2 of the drawings illustrates the apparatus positioned to remove the separated liner from the tubing;

FIG. 3 of the drawings is a sectional view taken along line 33 of FIG. 1B illustrating the position of the spear member prior to insertion between the liner and the tubing;

FIG. 4 is a sectional view of the upper portion of the liner confined to facilitate removal of the liner; and

FIG. 5 is a sectional view of the spear member taken along line 55 of FIG. 2 after insertion between the liner and tubing.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to FIGS. 1A and 1B of the drawings, an apparatus A is illustrated in a position downhole of production tubing B above the liner C mounted on the inner wall D of the production tubing. In the preferred embodiment of this invention, an upper portion E of the liner C has already been separated from the inside wall D of the production tubing by any suitable means such as a liner separating apparatus.

The apparatus A includes a body 10 to which is connected a mandrel 11 having a male threaded upper end adapted to be connected to a wire line actuated jar or jarring tool with a wire line connected thereabove (not shown) in the conventional manner. The mandrel 11 further has a male mounting member 11b extending from its lower end to releasably mount a bell-shaped housing 12 formed as a part of the body. The bellshaped housing 12 includes a recess 12a at its upper end which is adapted to fit over the male mounting member 11b and, shear pins 14 are inserted into engagement both with the lower mounting member 1 1b of the mandrel l1 and with the wall 12b which forms the recess 12a in the bell'shaped housing 12 such that the shear pins 14 releasably connect the bell-shaped housing 12 to the mandrel 11. The shear pins 14 may be sheared by exerting a predetermined amount of force on the mandrel 11 in a manner that is well known to those having skill in the art such that the mandrel 11 may be released from the housing 12 if necessary.

The housing 12 further includes a recess 12c formed by wall 12d. A longitudinal spear member 16 is eccentrically mounted in the recess in the housing 12 and extends downwardly to a tapered end 16a. An upper end 16b of the spear member 16 is threaded for threaded engagement with a correspondingly threaded hole 12c within the recess 120 but positioned off-center from the longitudinal axis of the housing 12. A set screw 17a extends through a hole (not shown) in the bell-shaped housing to secure the spear member 16 therein.

A spring member 20, which is a single-leaf spring member 20 extending outwardly from the spear member 16, is mounted at its lower end on the spear member 16 by mounting means such as screws 21a. The upper end of the spring member 20 has a vertical slot 20a therein; and a screw 23 preferably extends loosely through the slot 20a into threaded engagement with a suitable threaded hole (not shown) in the spear member 16 whereby the spring 20 is mounted so that its upper end may slide longitudinally relative to the screw 23 and the member 16, allowing the spring 20 to flex for yieldably engaging the inside wall D of the liner C as the apparatus is moved downwardly to a position just above the liner C.

The eccentrically mounted spear member 16 is flexible such that the spring member 20 pushes an outer portion 160 of the spear member against the inside wall D of the production tubing B whereby the tapered end 16a is positioned for insertion between the liner C and the inside wall D of the production tubing. Thus, the apparatus A is lowered in the production tubing to a position just above the liner C as shown in FIGS. 1A and 1B, and thereafter the tapered end 16a of the spear member is inserted between outside wall 17 of the liner and the inside wall D of the production tubing to initially separate the liner C from the inside wall forming a longitudinal reverse bend 24 in the liner C.

A latch member 25 is mounted by a pin 26 in slot 27 in a support 28, which is welded or otherwise affixed to the spear member 16 above the tapered lower end 16a. After the spear member 16 has been moved downwardly to the position illustrated in FIG. 2, a lifting surface 25a of the latch member 25 is positioned to hook under lower end 260 of the liner C so that the liner C may be lifted out. To secure the latch member 25 for lifting during the upward movement of the apparatus A, a surface 25b of the latch member 25 is positioned adjacent to a surface 27a of the recess 27 in this support such that the latch member 25 is restrained from rotation in a clockwise direction. it is also noted that a lower surface 25c is positioned a slight distance from a horizontal surface 27b of the recess such that the latch member may be rotated slightly in a counterclockwise direction as the spear member 16 is moved downwardly between the liner and the inside production tubing wall to insure that the latch member does not damage the liner during the downward movement. After the latch member 25 has been moved down past the lower end 26 of the liner, the center of gravity of the latch member is preferably such that the latch member 25 will pivot to the catch position of FIG. 2. Other means may be used to insure that the lifting surface 25a of the latch will hook under the bottom of the liner. For instance the latch member 25 may be resiliently urged outwardly from the spear member 16 by a spring mounted between the inside surface 16d of the spear and the latch in the same manner as the spring mounting for member 35 hereinafter described if desired. v

A roller 30 is mounted for rotation in a slot 31 in the support 28 on a pin 32 which extends across the slot into the support. A recess 16c is preferably provided in the inside surface 16d of the spear member 16 so that the roller 30 may be free to rotate therein. The function of the roller 30 is to cooperate with the tapered end 16a of the longitudinal member 16 and with a tapered surface 28a on the support 28, to engage and deform the longitudinal reverse bend 24 throughout the length of the liner.

To provide further means for lifting the liner C out of the production tubing D, a plurality of gripping devices such as barb members 35 and 36 are mounted on the spear member 16 to bite into the outside wall 17 of the liner as the liner is lifted out of the production tubing. The barb member 35 is pivotally mounted in a slot 37a in a support 37, which is welded or otherwise attached to the spear member 16, by means ofa pin 38. The barb member 35 has a sharp end 35a extending outwardly from the spear member 16 to actually engage and bite Dby.

into the liner C for facilitating lifting and removal of the liner C from the tubing B. A leaf spring 39 is preferably mounted by means of a screw 40 in a recess 41 in the inside surface 16d of the spear member 16 for resiliently engaging a surface 35b of the gripping member 35 so that, as the spear member 16 is moved downwardly between the liner C and the inside tubing wall D, the engagement of the barb member 35a with the liner C causes it to pivot upwardly against the spring 39 such that the sharp end 35a of the barb member will not bite into or damage the liner C. The spring 39 also urges the barb member 35 outwardly so that the sharp end 35a of the member 35 will bite into the outside wall 18 of the liner to assist the latch 25 in lifting the liner as the apparatus is moved upwardly. The barb member 35 further includes a surface 350 which will engage the inside portion 16d of the spear member such that the barb member is held in engagement with the outside liner wall as the spear member is moved upwardly.

in a similar manner the barb member 36 is mounted in a slot 43a in a support 43 which is welded or otherwise affixed to the inside portion 16d of the spear member 16. The barb member 36 is mounted for pivotal movement by a pin 44 which extends between the sides 43 of the slot in the support member; and, a leaf spring 45 is mounted onto the spear member 16 in a manner similar to the spring 39 for the barb 35, such that the barb 36 will also move counter-clockwise as the spear member 16 is moved downwardly to prevent damage to the liner, as explained in connection with the gripping member 35. The barb member 36 is also urged into engagement with the outside lining wall 18 to assist in lifting the apparatus out of the production tubing. It will be understood that additional gripping or barb members may be mounted on the member 16 for additional gripping action as desired.

ln the operation or use of the apparatus -A of the preferred embodiment of this invention, the upper portion E of the liner C has already been separated from the inside wall D of the production tubing by any suitable means such as a liner separating apparatus. The upper portion E, as illustrated in FIG. 3, has been crimped at sections 46a so that the upper portion E is spaced inwardly from the inside wall D such that pockets 46b are formed between the liner Cand the inside wall D of the production tubing B. a

The apparatus A is lowered into the productiontubing C to the position of FIGS. 1A and 1B; thereafter, the tapered end 16a of the spear member 16 is inserted between the liner C and the inside wall D of the production tubing B. As the spear member is moved downwardly the tapered end initially wedges between the outside wall 17 of the liner C and the inside wall D of the production tubing B thereby forming at least a portion of the longitudinal reverse bend 24 in the liner C. As the spear member continues to move downwardly, the tapered lower end 28a of the support 28 also serves toengage and also deform the liner into the reverse bend 24-. The roller 30, which is positioned outwardly from the support 28, rollingly engages the outside wall 17 of the liner C and further deforms the liner C so that the full reverse bend 24 of FIG. 5 is formed therein. sides 28b and 280 to widen the reverse bend 24 somewhat.

The support 28 is sufficiently large at As the roller 30 in the spear member 16 approaches the bottom bend 26a of the liner C a tapered end 12f on the housing wall 12d pushes tapered end 29 of the liner C into the recess 12c. The upper portion E of the liner is pushed into the recess 12c as the spear member 16 continues to move downwardly until the latch member 25 has cleared the bottom end 26a of the liner C so that the latch member 25 will pivot outwardly for engaging the bottom end 26a. Then the spear member 16 is moved upwardly so that the lifting surface 25a of the latch member engages the bottom end 26a. As the spear 16 is moved upwardly for the latch engagement, some of the top portion E of the liner C is moved out of the recess 12c; however, as illustrated in F IGS. 2 and 4, the remainder of the top portion E is combined within the recess 12c so that it will not interfere with the removal of the liner C from the tubing B.

The wireline then pulls the liner C out of the production tubing B. As the liner C is pulled out, the barbs 35 and 36 bite into the outside wall 17 to assist the latch member 25 in lifting the liner C out of the production tubing B.

Although a new and improved apparatus A has been disclosed herein for removing the liner C from the production tubing, the method of removing the liner may be practiced with other suitable means in addition to the apparatus A. In practicing the method of this invention a top portion E of the liner is first separated from the tubing B,thereafter a separating member is lowered into the production tubing B to a position just above the liner C. The separating member is then inserted between the liner C and the inside wall D of the production tubing B and, a substantially longitudinal reverse bend 24 is formed in the liner C as the separating member is moved the length of the liner C. The forming of the reverse bend 24 frees the liner C from the inside wall D of the tubing B so that it may be removed therefrom. The bottom end 26 of the liner C is engaged and the upper portion E of the liner C is confined so that the liner may be lifted out of the production tubing B.

In the method and apparatus of this invention discussed herein, the upper portion E of the liner C was already separated from the inside wall D of the production tubing B. It is to be understood that it is merely advantageous to separate the upper portion E of the liner prior to using of the apparatus of this invention. The initial separation of the upper portion E of the liner C does allow an operator to position the spear 16 more easily in a pocket 46b between the outside wall 17 of the liner and the inside wall D of the tubing; and, the upper end E of the liner is more easily confined to the recess 12c in the housing 12 if it has already been substantially reduced in diameter as illustrated in FIG. 3. However, it is within the scope of this invention to use the apparatus of the present invention to actually separate the entire liner from the production tubing and remove it therefrom.

The foregoing disclosure and description of the'invention are illustrative and explanatory thereof, and various changes in the size, shape and materials as well as in the details of the illustrated construction may be made without departing from the spirit of the invention. For example, it is within the scope of this invention to utilize the apparatus and method of this invention to remove a liner not only from production tubing, but also any tubular member such as casing.

lclaim: 1. Apparatus for separating a liner from the inside wall of a tubular member, comprising:

a. a central body adapted to be placed in said tubular member; and

b. separating means attached to said central body and extending therefrom for insertion between said tubular member and said liner to produce a reverse bend in said liner whereby said liner is substantially separated from said tubular member for removal therefrom.

2. The structure set forth in claim 1 including:

a spring member mounted on said separating means and extending into engagement with said tubular member to maintain said separating means against said inside wall of said tubular member thereby positioning said separating means in position for insertion between said liner and said tubular member.

3. The structure set forth in claim 1, including:

said central body having a recess therein adapted to receive an end of said liner in order to confine said end substantially in said central body to prevent said end from interfering with the removal of said liner from said tubular member.

4. The structure set forth in claim 1, including:

lifting means attached to said separating means for engaging one end of said liner after said separating means has been inserted between said liner and said tubular member whereby said liner may be removed therefrom.

5. The structure set forth in claim 4 wherein said lifting means includes:

a. a latch member including a lifting surface;

b. pivotal latch means pivotally mounting said latch member for movement on said separating means whereby said lifting surface is positioned to engage an end of said liner for removal of said liner from said tubular member.

6. The structure set forth in claim 1, including:

a barb member member mounted on said separating means for engaging said liner as said liner is removed from said tubular member.

' 7. The structure set forth in claim 6 including:

a. a sharp end on said barb member extending from said separating means to engage said liner for removal;

b. pivotal means pivotally mounting said barb member on said separating means;

c. spring means mounted on said separating means for urging said sharp end of said barb member into yieldable. engagement with said liner as said separating means is inserted between said liner and said tubular member; and

d. said barb member having a camming surface which engages said separating means such that said barb is held against pivotal movement as said apparatus removes said liner from said tubular member whereby said sharp end fixedly engages said liner to facilitate removal of said liner.

8. The structure set forth in claim 1 wherein said separating means includes:

forming means mounted on said separating means and cooperating therewith for forming a substantially longitudinal reverse bend in said liner whereby the diameter of said liner is reduced to facilitate removal of said liner from the tubular member.

9. The structure set forth in claim 8 in which said forming means includes:

a roller mounted for rotation on said separating means and extending in rolling engagement with said liner to facilitate insertion of said longitudinal member between said liner and said tubular member and form a reverse bend in said liner.

10. The structure set forth in claim 1, wherein said separating means includes:

a substantially longitudinal member tapered at one end whereby said tapered end is inserted between said liner and tubular member.

l l. The structure set forth in claim 10 including:

eccentric means for eccentrically mounting said substantially longitudinal member in said central body to position said longitudinal member in proximity to said inside wall of said tubular member.

12. The structure set forth in claim 1 wherein said central body includes:

a. a mandrel b. a bell-shaped housing attached to said mandrel;

and

c. mounting means for mounting said separating means with said bell-shaped housing.

13. The structure set forth in claim 12 wherein said bell-shaped housing includes: 7

a recess therein adapted to receive an end of said liner in order to confine said end to said housing to prevent said end from interfering with the removal of said liner from said tubing member.

14. The structure set forth in claim 12 including:

releasable means for releasably mounting said bellshaped housing on said mandrel whereby said mandrel is releasable from said bell-shaped housing by the exertion of a predetermined force.

15. The structure set forth in claim 12 including:

a. said separating means including a substantially longitudinal member tapered at one end; and

b. said bell-shaped housing having a recess therein;

and

c. mounting means for mounting said substantially longitudinal member on said bell-shaped housing and within said recess therein whereby an end of said liner is confined in said recess adjacent said longitudinal member to prevent said end from interfering with the removal of said liner from the tubular member.

16. A method of separating a liner from the inside wall of a tubular member, comprising the steps of:

a. placing a separating member in said tubular member; and

b. inserting said separating member between said liner and said tubular member and moving said separating member the length of said liner; and

c. forming a substantially longitudinal reverse bend in said liner as said separating member is moved the length of said liner whereby said liner is substantially separated from said tubular member for removal therefrom.

17. The method set forth in claim 16, including:

separating a top portion of said liner from said tubular member to provide a pocket into which said separating member is inserted.

18. The method set forth in claim 16, including:

engaging an end of the liner after said liner has been separated from the tubular member for removing liner therefrom.

19. The method set forth in claim 16, including:

confining an end of said liner whereby said end will not interfere with removal of the liner from said tubular member. 

1. Apparatus for separating a liner from the inside wall of a tubular member, comprising: a. a central body adapted to be placed in said tubular member; and b. separating means attached to said central body and extending therefrom for insertion between said tubular member and said liner to produce a reverse bend in said liner whereby said liner is substantially separated from said tubular member for removal therefrom.
 2. The structure set forth in claim 1 including: a spring member mounted on said separating means and extending into engagement with said tubular member to maintain said separating means against said inside wall of said tubular member thereby positioning said separating means in position for insertion between said liner and said tubular member.
 3. The structure set forth in claim 1, including: said central body having a recess therein adapted to receive an end of said liner in order to confine said end substantially in said central body to prevent said end from interfering with the removal of said liner from said tubular member.
 4. The structure set forth in claim 1, including: lifting means attached to said separating means for engaging one end of said liner after said separating means has been inserted between said liner and said tubular member whereby said liner may be removed therefrom.
 5. The structure set forth in claim 4 wherein said lifting means includes: a. a latch member including a lifting surface; b. pivotal latch means pivotally mounting said latch member for movement on said separating means whereby said lifting surface is positioned to engage an end of said liner for removal of said liner from said tubular member.
 6. The structure set forth in claim 1, including: a barb member member mountEd on said separating means for engaging said liner as said liner is removed from said tubular member.
 7. The structure set forth in claim 6 including: a. a sharp end on said barb member extending from said separating means to engage said liner for removal; b. pivotal means pivotally mounting said barb member on said separating means; c. spring means mounted on said separating means for urging said sharp end of said barb member into yieldable engagement with said liner as said separating means is inserted between said liner and said tubular member; and d. said barb member having a camming surface which engages said separating means such that said barb is held against pivotal movement as said apparatus removes said liner from said tubular member whereby said sharp end fixedly engages said liner to facilitate removal of said liner.
 8. The structure set forth in claim 1 wherein said separating means includes: forming means mounted on said separating means and cooperating therewith for forming a substantially longitudinal reverse bend in said liner whereby the diameter of said liner is reduced to facilitate removal of said liner from the tubular member.
 9. The structure set forth in claim 8 in which said forming means includes: a roller mounted for rotation on said separating means and extending in rolling engagement with said liner to facilitate insertion of said longitudinal member between said liner and said tubular member and form a reverse bend in said liner.
 10. The structure set forth in claim 1, wherein said separating means includes: a substantially longitudinal member tapered at one end whereby said tapered end is inserted between said liner and tubular member.
 11. The structure set forth in claim 10 including: eccentric means for eccentrically mounting said substantially longitudinal member in said central body to position said longitudinal member in proximity to said inside wall of said tubular member.
 12. The structure set forth in claim 1 wherein said central body includes: a. a mandrel b. a bell-shaped housing attached to said mandrel; and c. mounting means for mounting said separating means with said bell-shaped housing.
 13. The structure set forth in claim 12 wherein said bell-shaped housing includes: a recess therein adapted to receive an end of said liner in order to confine said end to said housing to prevent said end from interfering with the removal of said liner from said tubing member.
 14. The structure set forth in claim 12 including: releasable means for releasably mounting said bell-shaped housing on said mandrel whereby said mandrel is releasable from said bell-shaped housing by the exertion of a predetermined force.
 15. The structure set forth in claim 12 including: a. said separating means including a substantially longitudinal member tapered at one end; and b. said bell-shaped housing having a recess therein; and c. mounting means for mounting said substantially longitudinal member on said bell-shaped housing and within said recess therein whereby an end of said liner is confined in said recess adjacent said longitudinal member to prevent said end from interfering with the removal of said liner from the tubular member.
 16. A method of separating a liner from the inside wall of a tubular member, comprising the steps of: a. placing a separating member in said tubular member; and b. inserting said separating member between said liner and said tubular member and moving said separating member the length of said liner; and c. forming a substantially longitudinal reverse bend in said liner as said separating member is moved the length of said liner whereby said liner is substantially separated from said tubular member for removal therefrom.
 17. The method set forth in claim 16, including: separating a top portion of said liner from said tubular member to provide a pocket into which said separating member is inserted.
 18. The method set forth in claim 16, including: engaging an end of the liner after said liner has been separated from the tubular member for removing liner therefrom.
 19. The method set forth in claim 16, including: confining an end of said liner whereby said end will not interfere with removal of the liner from said tubular member. 